1. Technical Field
The present invention generally relates to a shiftlever mechanism for an automatic transmission, and deals more particularly with a shiftlever mechanism in which a shift into overdrive can be performed by moving the shiftlever in the direction of shifting.
2. Background Art
The selection of overdrive has generally been performed by turning on or off an overdrive switch, which is located in the dashboard or near the shiftlever of the vehicle. However, this arrangement is not only troublesome for the driver, because he has to manipulate the overdrive switch and then confirm the result, but is unfavorable for safe driving of the vehicle, because in operating the switch and in confirming the result, the driver's eyes are necessarily diverted from the driving view.
To solve this problem, a shiftlever mechanism for an automatic transmission, shown in FIG. 7, has been proposed which is disclosed in Japanese Utility Model Laid Open No. 75120/83. In this proposal, the shiftlever a is divided into an upper part b and a lower part c so that the upper part b and the lower part c move in unison when shifting the shiftlever in the longitudinal direction of a vehicle, but when shifting into overdrive, the upper part b is tilted in the transverse direction with the lower part c as its fulcrum, by which motion an overdrive switch d of a rotary type, which is disposed in the direction of such transverse motion, is turned on or off.
Also, in order to permit selection of overdrive at every position of forward shifts, a plate f having a length that covers all the forward shift positions is provided to the moveable contact point e of the overdrive switch d.
One deficiency in this construction is that there can easily be cases where the shiftlever is unwittingly shifted into the overdrive position by tilting the shiftlever, thereby turning the overdrive switch on or off, in the process of shifting if the driver errs in controlling the force he applies to the shift lever.
Since misshifting in selecting overdrive is unfavorable for fuel economy and power output, a shiftlever mechanism for automatic transmission that enables unfailing selection of overdrive by moving the shiftlever in the direction of shifting would be desirable.